There is known a turbocharger provided with a compressor in which a variable diffuser located between a compressor wheel and a scroll flow passage is provided with plural movable vanes and a cross-section area of the variable diffuser is changed by rotating the plural movable vanes (see patent literature 1). Furthermore, with respect to an internal combustion engine equipped with a turbocharger, there is known the internal combustion engine including an EGR passage for recirculating exhaust gas passed through a turbine and an exhaust gas purifying catalyst to an upper stream of a compressor (see patent literature 2). In addition, there are Patent Literatures 3-5 as prior art references in relation to the present invention.